Reassessing ‘The Effect of the Seattle Police-Free CHOP Zone on Crime’

A counterfactual critique

Charles C. Lanfear

University of Cambridge

Piza & Connealy (2022)

 

Purpose

Police withdrawal occurring during CHOP supposedly provides a quasi-experiment of what happens when you remove policing from an area

They specifically refer to police abolishment in the paper, implying abolition would result in CHOP-like conditions

Their strategy

Synthetic control

Their findings

Counterfactuals

Potential Outcomes


Ignorability


What is our counterfactual?

Seems like this is really about Y0A not being what they think it is?

Piza & Connealy Revisited

Implicit causal model

G chop CHOP Zone crime Crime chop->crime place Measured Place Characteristics place->chop place->crime protest Protest protest->chop protest->crime

Assumptions:

  • Primary: Protest is independent of CHOP Zone and/or Crime
  • Secondary: No unmeasured Place Characteristics are relevant

Timeline

Problems

It is not conceivable the police pullout would have occurred absent the large-scale protest and repeat conflicts with police

The police pulled out because clashes with police were escalating.

No comparison units had a large-scale protest against police occurring in them; places with similar crime rates leading up to CHOP did not have similar reasons for those crime rates.

Show chop zone pictures

Show pictures not during chop

Huge fucking influx of people prior to CHOP

Secondary Issues

  • Interference: Protests and police withdrawal caused shifts across city

What did crime actually do after the pullout?

Show trend plots of rapid decline at start, rapid increase at end

Police-reported crime in CHOP zone is in large part due to police activity

This reflects that police left precinct to de-escalate (prevent more contacts) and things re-escalated, briefly, when they returned.

Capitol Hill

List of measured place characteristics; do these explain cap hill?

History of protests, protests after CHOP

Similar patterns in crime occurred in Capitol Hill absent police withdrawal on July 25th, 2020 due to detention center protest.

This is because Capitol Hill is an unusual area of Seattle with physical and social characteristics that make protests and conflicts with police more likely

What is the counterfactual?

Observed

How many reported crimes occurred after police withdrew to de-escalate conflict with an existing large-scale protest against police

Counterfactual

How many reported crimes would have occurred if neither the protest nor the withdrawal occurred

Critically, the difference between these does not tell us if withdrawing from the East Precinct increased crime

Summary

Design

  • Theory needs to be correct
  • Theory requires contextual understanding

Substance

  • Estimate does not correspond to any useful estimand
  • “CHOP effect” is not likely to generalize

Feedback and Questions

Contact:

Charles C. Lanfear
Institute of Criminology
University of Cambridge
cl948@cam.ac.uk